Composite materials exhibit a relatively high strength-to-weight ratio that renders them usable for aircraft applications, particularly skin panels. However, since an aircraft is exposed to lightening strikes in flight, precautions must be taken to effectively ground all components of the aircraft relative to one another in order to dissipate the electrical energy of a lightening strike. This has heretofore presented a problem since composite materials generally contain a conductive fiber, for example, carbon fibers that are insulated from one another by a resin matrix. Where the fibers are continuous the electrical energy of the lightening strike is dissipated into the atmosphere. However, when electrical continuity is disrupted, the electrical potential tends to build up, resulting in an arc which, in some cases, can destroy the composite structure of its supportive structural elements.
A specific problem that is addressed by the instant invention is the problem experienced when an electrically conductive bolt, rivet, or the like, is seated in an aperture in a composite material. When lightening strikes the composite material, the electric energy is conducted by the carbon filaments of the composite until a bolt or fastener is reached. Because the bolt is relatively more conductive than the carbon fibers, the electrical energy tends to follow the bolt. However, because the conductive path offered by the bolt is discontinuous, the bolt often melts or the holding power thereof is compromised due to subsequent arcing of the electrical energy.